Patrick Haggard is a neuroscientist who collaborated with Benjamin Libet and reproduced some of the 1983 Libet experiments.

Haggard is convinced that "conscious will" is an illusion, agreeing with the claims of Daniel Wegner. In a joint article with Libet in 2001, Haggard said:

The doctrine of conscious free will seems, at first sight, to be strongly dualist, and therefore incompatible with the reductionism of modern brain science: how can a mental state (my conscious intention) initiate the neural events in the motor areas of the brain that lead to my body movement? Modern neuroscience would reverse these causal roles, and would describe conscious intention as a consequence or correlate of neural preparation of action.
(Conscious Intention and Brain Activity, Journal of Consciousness Studies 8 (11):47-63)

Although neural activity clearly precedes the moment of conscious awareness of intentions, Haggard is not justified in saying that "preparatory brain activity causes our conscious intentions." In the two-stage model of free will, the preparatory brain activity may correspond only to the first stage, one that generates alternative possibilities for action. The actual decision is not yet made.